> I don't know how they're joined--bolted? Riveted? For black metal, it's the most obvious method — welding. For sheet metal, it's clinching, snaps, or, more

> I don't know how they're joined--bolted? Riveted? For black metal, it's the most obvious method — welding. For sheet metal, it's clinching, snaps, or, more rarely, threaded fasteners.